BLUE JEAN BABY: Scott Morrison’s 3×1 denim label is known for its unique retail concept in Manhattan’s SoHo, and now Paris is getting its own turn. The brand will open its first women’s shop-in-shop at Le Bon Marché, which will kick off with a two-day launch on Sept. 26 and 27. The 700-square-foot space will mimic the label’s New York flagship, complete with a denim ‘wall’ showcasing an array selvedge fabrics the brand uses for its denim products, and also marks the first time the French department store has ever given a denim brand as much real estate. The shop will carry 3×1’s core collection of bestsellers as well as a few styles exclusive to Le Bon Marché. And, if customers purchase any of those exclusive silhouettes, they’ll be able to choose their own buttons and rivets — a custom service that, until now, has only been available at the New York shop.